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Bring Back 1962-63

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  1. I'm sorry but this is almost wholly wrong! You have misread the chart and your comments are extremely misleading to say the least. The chart shows a typical transient and more mobile flow, with a succession of ridges and troughs in all regions. Let's look at the latest forecasts: Starting with ECM to coincide with their chart that you posted out to T+240 (or Dec 17th). The AO is +ve out to at least Dec 15th. The control run (black) drops to slightly -ve by day 9 but note that most of the ens members remain +ve. The mean briefly goes to neutral around day 10 but recovers slightly after that. Even towards the end of the period shown (to day 15) more members favour a +AO than a -ve AO. GEFS is even more +ve with only a few ens members going slightly -ve temporarily in week 2. While I'm about it, here's the latest NAO chart. Almost entirely +ve throughout with just the control run and a few members going slightly -ve later in week 2. Again the mean stays +ve throughout with more members more strongly +ve than -ve throughout. The EPO goes +ve early in week 1 and stays +ve thereafter but with an increasing spread of +ve and -ve ens members during week 2 onwards. Overall while there are slight variations on the details, the broad patterns are quite clear and consistent with the key teleconnections and the GSDM. One cannot just conjure up a cold spell out of nothing! There have been far too many misleading posts on this thread. December may deliver one or two very brief colder snaps, perhaps even with brief snowfalls but overall, all the background signals point to a strengthening polar vortex and a much more mobile pattern. Zonal at times and with just transient ridges but with no longer last blocking patterns setting up. We still have 2 months left of winter proper after this rather AN and pretty mobile December for eCONUS, the UK and western Europe and the mid latitudes more generally. So, plenty to be resolved during the next few weeks and we can focus on evolving patterns to get a better idea of what January has in store. David
  2. Hi BL74, you did not elaborate on your comment but it is important to read these charts accurately and put what they show into context. Reading from top to bottom, we have the activity for the past month down to the forecast line (Dec 6th) and then the forecast for the next 7 days below the line. The warm colours (yellow/red shades) are generally westerly wind anomalies and the cold colours (blues/purple shades) are generally easterly trades. The deep red (pink/white centre) coincided with the peak of the slightly more active phase of the MJO in the 3rd week of Nov and that was centred just west of the dateline (circa 160E-170E). Just prior to that (Nov 16th-20th) it did cross the dateline but that rapidly faded. Overall, the temporary and very weak westerlies are fading and have been predicted to do so for some time (I posted on it several pages back on this thread). That current small red blob centred at 160E is on the way out. Note the blues taking over in that region right now. In fact there is even a bit of purple showing up early next week right on the dateline. I reported extensively on that tiny red/yellow area further east towards the EPAC (circa 100W-90W) and that is also slowly weakening. When I reported just 5 days ago, there was a hint that the I/O standing wave was showing signs of weakening and edging eastwards. We can see that there was a temporary push into it during the first week of Dec with the reds making it to 50E-60E on Dec 3rd. These too have already faded and retreated and the standing wave is rapidly regaining strength again. In fact some purples are showing up again at 60E-70E early next week. What is also significant is the spread of the blues right through to the WPAC. This was generally expected with the MJO in its inactive phase in the Pacific for at least the next 2 weeks. The GWO and GLAAM and FT are all -ve now (as predicted by some of us) and MT will follow suit shortly. The +ve EAMT is purely temporary and it too will weaken during the next few days and looks set to be -ve for at least 2 weeks. David
  3. Low solar "can" be associated with colder winters. More often the coldest winters tend to be just after the solar minimum. We are right at the minimum right now. There is usually a run of 3 winters which "can" be influenced and any combo of 0, 1, 2 or all 3 can see colder patterns. The last minimum was in 2009 and there was a triple hit. In the UK (and Western Europe) we had a cold winter in 2008/9, 2009/10 and the coldest Dec since 1890 in 2010/11 (although the 2nd half of that winter was mild). I haven't got time to go into the causes and potential impacts right now but there are several good papers that I placed in the Research Portal - here are 2 lists of the titles from the index: Solar Cycle (SC), Solar Oscillation and Grand Maxima & Grand Minima: Do trend extraction approaches affect causality detection in climate change studies? High‐latitude influence of the quasi‐biennial oscillation Solar and QBO Influences on the Timing of Stratospheric Sudden Warmings Solar forcing of winter climate variability in the Northern Hemisphere Sunspots and the Solar Max - What Exactly is a Sunspot? Sunspots, the QBO and the stratosphere in the North Polar Region – 20 years later The Influence of the Solar Cycle and QBO on the Late-Winter Stratospheric Polar Vortex The Influence of Solar System Oscillation on the Variability of the Total Solar Irradiance Transfer of the solar signal from the stratosphere to the troposphere: Northern Winter Sunspots and Sunspot Cycle (SSC): Analyzing the combined influence of solar activity and El Niño on streamflow across southern Canada Coherence among Northern Hemisphere land, cryosphere & ocean responses to natural variability & anthropogenic forcing during satellite era Do trend extraction approaches affect causality detection in climate change studies? Influences of the 11-year sunspot cycle on the stratosphere – and the importance of the QBO Influence of the sunspot cycle on the Northern Hemisphere wintertime circulation from long upper-air data sets The Influence of Solar System Oscillation on the Variability of the Total Solar Irradiance Sunspots and ENSO relationship using Markov method Sunspots and the Solar Max - What Exactly is a Sunspot? Just click on the title to go to an abstract/summary and then you can decide if you wish to use the link there to the full paper. The range of papers is from simple guides through to much more technical aspects of the topic. Several of the titles appear under both headings. Hope you find this useful. David
  4. I'm sorry but I'm afraid that your comment is very wide of the mark. We look at all the main teleconnections and it is these that drive the broader patterns and the Pacific is merely a part of it all - have you stopped to think what drives the Pacific? Our references to the NAO were far more to do with responding to so many on here going for a -ve NAO when we stated that it would turn +ve. In any case a -ve NAO, particularly a west based one is very useful for eastern CONUS usually allowing a trough to develop over there, just west of the ridge in the western N Atlantic. You need to look at the wider picture and the trough ridge alignments - the EPO, PNA and NAO are just a small part of that process. David
  5. GENERAL TELECONNECTIONS UPDATE Hi Tom, an excellent post and one which I wish to elaborate on. I haven't got that much time - so no long explanations of what all the charts are showing (that'll have to wait until next week) just a brief comment below each one. In essence "nothing" has really changed despite the usual variations in the longer term model output which provoked both excitement and disagreements on here, even among some high profile posters. As Tom @Isotherm, Tams @Tamara, several others and myself have been saying, it's the teleconnections (background signals) that drive the models "NOT" the other way around. Unfortunately, even these have been misinterpreted by several analysts both on social media and then reported on here. Nobody will get it right all of the time and it simply should not be a competition. It's so important to try and adopt an objective analysis and not allow weather preferences to obscure what the underlying trends are telling us. At least some of you have had an early taste of winter and although December is likely to be an AN month overall (both in eCONUS and the UK and Western Europe) that does not rule out fleeting, transient colder snaps which can still deliver a brief snow cover. EDIT: While I've been preparing this post I see that Tams @Tamara has just posted wrt to the QBO and the stratosphere and I completely concur with her comments. That saves me some time and I'll focus on the GWO, GLAAM, the torques, ENSO and the MJO. Let's have a look at the next few weeks through to the Christmas period. We have the usual 2 day time lag on these AAM and torque charts. The colour has not yet been changed for the new month but the signs are that we are entering a very similar orbit to the last one (not the much higher GLAAM that several had forecast). In fact, GLAAM looks to have already peaked and is marginally lower than mid November. After looping back to p8/1, it seems set to drop back into p1/2 and embark on a slightly lower orbit. Just a reminder of the phase space chart. Relative AAM tendency has completed its temporary rise into moderately +ve territory but is falling back quickly. Total GLAAM (not shown) never quite went +ve and is also falling now. FT made a brief foray into +ve territory but it was this that several commentators misread. It is so important to look at the geographical distribution of FT. Most of the +ve FT has been in the higher latitudes - around 50N-60N and 50S-60S but we are looking for what is going on in the tropics and sub-tropics. There was a very brief period last week of weakly +ve FT at 15N-20N but this is already turning -ve again. We need a more sustained period of +FT down there to kick start a more progressive/higher orbit GWO. The next 2 to 3 weeks do not look like delivering that. There have been a few posts wrt a +ve EAMT and the impacts from that downstream. GLMT tends to follow FT (not always) and has struggled to go to strongly +ve levels. All the regional torques went briefly +ve - given the 2 day time lag, I believe that they are all going -ve again right now. For EAMT, I also follow the jet stream through south east Asia, the pressure distribution and also Gravity Wave Drag all of which can give a heads up several days beforehand and to me I feel that EAMT will be -ve again for the next week or so and maybe through week 2 as well. Moving on to ENSO, this is another area that has been badly misunderstood. I have produced 3 long ENSO posts since mid-October explaining that the trend had changed and I provided a bundle of evidence and yet so many commentators completely overlooked this or missed the obvious signs altogether! We are in a really weak near neutral to very slightly Nino-like ENSO base state. Far too weak to correlate to a long period with a -ve NAO which Tom and I (and several others) said would turn +ve by early Dec. No time to post all the Nino region charts - so I'll just state the 6z temp anomaly readings: Nino 4 = +0.726; Nino 3.4 = +0.160; Nino 3 = + 0.220; Nino 1+2 = +1.148 The is definitely not a Modoki of any kind as I've been saying for all of November - quite the opposite. The EPAC has warmed but I shall say right now, that this is due to the legacy of kelvin wave 5 and is NOT an early sign that the warmer waters there will spread westwards to produce a basin wide El Nino! KW5 has now reached the EPAC. It has been steadily weakening with SUB anomalies not even over +1c now. That patch of warmer SUBs is close to the Ecuador coast and "must" rise to the surface there as it overrides the colder denser SUBs at 100 m from the Peruvian/Humboldt current. Colder (or less warm) waters always follow on behind the warm water compression created by a kw. In this case we have quite strong -ve SUBs that were at 150m to 100m (they have weakened marginally). I said that these would cool the surface layers in the CPAC and that Nino 3.4 would fluctuate around 0c (anomalies of around +0.2c to -0.2c) for the next couple of weeks and this is now clearly happening in the last few days. Now in the far WPAC we have what looks like KW6. At this stage it looks like being a very weak affair and has actually cooled very slightly and regressed westwards. It may just sit there and will need assistance from the MJO (when it might reach the Pacific again towards the end of Dec - more later on that) and from higher GLAAM and the GWO moving into a higher orbit. I make a lot of use of this superb chart. It's great for identifying trends. It's particularly useful very early in the month as we can compare the current anomalies to the average anomalies for each of the last 3 months. Remember we had that weak El Nino in the Spring which cooled to neutral in the early summer. In Aug/Sept there was some talk of La Nina conditions starting to take hold. These were premature and kw5 started to influence things. The warm pool started to spread across all bar the EPAC and peaked around the 2nd week in Oct. That's where some of the LRFs started to go for a far more Nino-like base state and, with the colder EPAC, a Modoki. One needs a succession of stronger kws + WWBs and more help from GLAAM and the MJO to establish a Nino. Even back in early Oct we could see the colder waters following on behind kw5. During Nov we saw kw5 weaken but push on through to the EPAC (as described earlier). Now kw6 shows up in the far WPAC but compare the bottom two sections of the chart. As I mentioned it has weakened during the last few weeks and slightly regressed westwards. The colder SUBs below have also weakened but we can see essentially ENSO neutral conditions in Nino 4 (to a lesser extent - it may stay sl +ve), 3.4 and soon Nino 3 and only Nino 1+2 staying +ve for the rest of Dec. The very weak temp contrasts also extend to the adjacent sub-tropics which is a convection inhibitor before we even consider the MJO and other factors. Moving on to what's going on above the surface.- I see that several posts have the latest MJO RMM phase charts. I see that GEFS has finally joined its ECM cousin and the other models in dropping the P2/3 progression in moderate amp and goes back into the COD for a week or two with the inactive phase. We need to look beyond these charts. For a few months now the Pacific has NOT responded in the way that one would normally expect. We've had a number of promising signs with MJO cycles, WWBs and kws all fading. We have an even longer term ocean-atmosphere disconnection. We've also had that I/O standing wave. There it is (the dark blue colours) centred around 90E. It has been there for a few months. It's a region of higher pressure with relatively cool and very dry air. If anything, it strengthened further during Nov (the purple colours) but there just "may" be signs of it weakening again and also just starting to edge eastwards - still painfully slow progress. The blue colours show easterly trade anomalies and the yellow, orange and red shades westerly wind anomalies. That red strip close to the dateline was associated with the last pass of the MJO through the Pacific phase. Again it looked really promising but just look how quickly it subsided again and the short term forecast to Dec 6th shows that easterly trades will again take over in the CPAC and WPAC. Those warmer colours at 120W to 90W are associated with kw5 reaching the EPAC with weak westerlies there for several weeks. MJO forecasts are extremely fickle and very variable at the best of times and week 2 charts often change appreciably - so looking at the next 40 days is a bit of a lottery! On this chart the cooler, drier phases are in green and the warmer, moister phases in yellow. Focusing only on the Equator we can see the last Pacific MJO pass fading in the EPAC and the inactive phase further west. Then we have that much more active phase set to enter the far WPAC later on in week 2....but it too is predicted to rapidly weaken as it move into the trop Pacific. The CFS forecast does show it regenerating again as it reaches CPAC and EPAC ENSO regions and then it is followed by a very weak inactive phase and the next active phase around mid Jan. The MJO cycle is typically 30 to 45 days but can vary - as we well know! More on this at the end. We would need to clear the "blocked" Pacific (not HP but the ocean-atmosphere disconnect and that I/O standing wave with a strong dampening effect) to see a stronger response to MJO passes. In harness with higher GLAAM (and torques) and the GWO moving into a higher orbit and into the Nino attractor phases (5,6,7) we need to see increased WWBs and a succession of stronger kws and that would establish a slightly stronger more Nino-like base state for the 2nd half of Winter. (I actually favour a La Nina developing in the Spring/early Summer but that's a long way off). The chart above shows the impact of kws on the upper ocean surface. We can see the strong kw associated with the peak of the weak El Nino in March which quickly weakened. There were two more attempts to form kws in June and Aug but they both faded in situ. Then kw5 did develop and make it across. In the bottom left of the chart, those slightly warmer colours are kw6. We do need to monitor that one. I've no more time to show more MJO or other charts. Overall, we have weak to sl -ve GLAAM, a very neutral ENSO base state, no chance of an early SSW (at least until much later in the winter and that's by no means certain either) , the QBO not quite completing its transition to its easterly phase, the I/O s/w dampening Pacific activity, the NAO and AO likely to stay mostly +ve for this month. So all that does not look great for the first half of winter. However, there are several slight glimmers of hope. Even during this month, most of the signals are relatively weak and no key teleconnection is particularly dominant. The next GWO orbit towards Christmas/New Year may go rather higher - perhaps enough to shift the I/O s/w, unblock the Pacific, creating stronger WWBs and kw activity (reinvigorating kw6) and giving the MJO a better chance of stronger Pacific phases. Perhaps this will see Jan as a transition month and then a colder back end to Winter. Right now, Tom's LRF looks spot on to me but only time will tell. David
  6. WHAT AN EXTRORDINARY AND TIMELY COINCIDENCE Firstly, a Happy Thanksgiving to all of you across "the pond" and a Happy Thursday to everyone else! A brand new paper has just been published (this Monday) and it's open access. It covers exactly what a number of us have been discussing wrt the ENSO base state, the MJO phases and the NAO as well as predicting changes in seasonal wave lengths. Here's a link to the Research Portal entry: ENSO Modulation of MJO Teleconnections to the North Atlantic and Europe Plain Language Summary: The Madden‐Julian Oscillation (MJO) is the dominant source of differing weather conditions in the tropics on timescales within a season. The remote linkage (teleconnection) from the MJO to the North Atlantic‐European (NAE) region provides a source to modify or persist weather conditions and add predictive power to weather forecasts on 10‐ to 30‐day timescales. The El Niño‐Southern Oscillation (ENSO) has an influence on the seasonal climate state, through which the waves and linkages from the MJO to the NAE region travel. Here we find a robust dependence of these teleconnections from the MJO to NAE weather regime patterns on the ENSO state, such that under certain states of the MJO, certain regimes occur more than twice as often. The different sources and pathways also become clearer, with the teleconnections travelling via the troposphere and the stratosphere. This dependence on ENSO state has significant implications for predictions on 10‐ to 30‐day timescales. I'm working now but when I do my next ENSO update in a week or so, I'll review this highly important paper. David
  7. ENSO Modulation of MJO Teleconnections to the North Atlantic and Europe Authors: R. W. Lee, S. J. Woolnough, A. J. Charlton‐Perez and F. Vitart Published online: 25th November 2019 Abstract: The teleconnection from the Madden‐Julian Oscillation (MJO) provides a source of subseasonal variability and predictability to the North Atlantic‐European (NAE) region. The El Niño‐Southern Oscillation (ENSO) modulates the seasonal mean state, through which the MJO and its teleconnection pattern propagates; however, its impact on this teleconnection to the NAE region has not been investigated. Here we find a robust dependence of the teleconnections from the MJO to NAE weather regimes on the phase of ENSO. We show that the MJO to NAO+ regime tropospheric teleconnection is strongly enhanced during El Niño years, via enhanced Rossby wave activity, and suppressed during La Niña. Conversely, the MJO to NAO− regime stratospheric teleconnection is enhanced during La Niña years and suppressed during El Niño. This dependence on the background state has strong implications for subseasonal predictability, including interannual variations in subseasonal predictive skill. Plain Language Summary: The Madden‐Julian Oscillation (MJO) is the dominant source of differing weather conditions in the tropics on timescales within a season. The remote linkage (teleconnection) from the MJO to the North Atlantic‐European (NAE) region provides a source to modify or persist weather conditions and add predictive power to weather forecasts on 10‐ to 30‐day timescales. The El Niño‐Southern Oscillation (ENSO) has an influence on the seasonal climate state, through which the waves and linkages from the MJO to the NAE region travel. Here we find a robust dependence of these teleconnections from the MJO to NAE weather regime patterns on the ENSO state, such that under certain states of the MJO, certain regimes occur more than twice as often. The different sources and pathways also become clearer, with the teleconnections travelling via the troposphere and the stratosphere. This dependence on ENSO state has significant implications for predictions on 10‐ to 30‐day timescales. Link to full article - website version: https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2019GL084683 Link to full article - pdf version: https://agupubs.onlinelibrary.wiley.com/doi/pdf/10.1029/2019GL084683
  8. MORE ABOUT THE GSDM, THE GWO, GLAAM AND THE TORQUES AND WHY THEY ARE SO IMPORTANT Some members may be a little puzzled with a number of posts on this thread referring to the GSDM (Global Synoptic Dynamic Model), the GWO (Global Wind Oscillation), GLAAM (Global Atmospheric Angular Momentum), FT (Frictional Torque) and GLMT (Global Mountain Torque and all the regional torques). In this post I shall explain a little more about these and why they are so important in our understanding of what controls the broader patterns, assess the key teleconnections and how they dominate and interact with each other and give us a heads up on upcoming changes. As we always say it is this which drives the model output not the other way around. 18 months ago, I did a specialist post on this topic on the Teleconnections thread. I thought that rather than simply just direct you to that post (which I will!), that I would "freshen it up" and present a shorter version of it on this thread. I hope that those of you wishing to learn more about this will find this very useful when you read our posts covering this topic. To give you an idea of its value, Tom @Isotherm uses it as the basis for (and a key component of) his excellent LRFs. Tams @Tamara taught me all about the ins and outs of the subject during the last 3 years and its application throughout the year with all the seasonal variations (and I'm still learning things like changes in seasonal wavelengths!). This filled a vast gap in my many years of studying the weather and if I can learn new concepts during my 60s then surely almost anyone can! The GSDM was jointly developed by two research scientists in the early 2000s - Dr Klaus Weickmann and Edward K Berry (not to be confused with Dr Edwin Berry - a climatologist). They were pioneers in their field and worked for NOAA from the late 1990s until around 2014 and produced a number of key papers, almost all of which you'll find in the Research Portal where the index includes headings for all the main teleconnections, the GWO, AAM and the torques, ENSO, MJO, SPV, SSWs as well as a GSDM heading. After leaving NOAA, Klaus and Ed worked for a private Met outfit for several years and used their techniques to produce LRFs and seasonal forecasts. Zac @Snowy Hibbo and I tried to track them down as we had some queries to put to them. Zac found an email address for Ed. I contacted him and he responded immediately. Klaus retired a couple of years ago but Ed is still active working within this field but is looking for work and funding to develop his research even further and put it to greater use. He is delighted that a small group of us are using the GSDM. We remain in email contact with him and he always responds quickly. We often wondered why some of the larger Met Offices do not make more use of the GSDM and if they do to what extent. My brother works at the UK Met Office HQ and about a year ago he forwarded an email of mine to their head of LRFs there (Dr Adam Scaife). Strangely, UKMet only indirectly looked at AAM and the torques and used different terminology and were not familiar with the GSDM! Then this summer, out of the blue, I received an email from Adam enquiring about it all and particularly about AAM. Still early days but it looks like they will be starting to embrace it from now on. We also believe that most of the other models only partially factor in some of these key teleconnections. We should see vast improvements once models are upgraded so that NWP can take account of all the components of the GSDM. Rather than me go into a lengthy explanation of the GSDM and its applications, Ed Berry kindly forwarded to me last year, a link to a YouTube video that covers one of his presentations to an AMS conference. The video is behind a paywall but Ed is happy for it to be shown on weather forums to give the GSDM and his work more exposure. Although there are many YouTube videos on various aspects of meteorology, such as ENSO, the MJO and SSWs, no one had produced one on this topic. This is not exactly a beginners guide but it's not far off it and I highly recommend viewing it for learners as well as those members with more experience. I copy the whole of my Research Portal entry below, which slightly repeats part of what I said above.: What is the GSDM and how does it help with subseasonal weather forecasts? A YouTube Presentation Presentation By: Edward K Berry (Senior Weather-Climate Scientist) Presentation Event: American Meteorology Society - Student Chapter, College of DuPage, Chicago Presentation Date: 28th March, 2018 Summary: Leading meteorological scientists Ed Berry and Dr Klaus Weickmann jointly developed their GSDM (Global Synoptic Dynamic Model) while they were working at NOAA in the late 1990s and earlier years of this century. They also devised the GWO (Global Wind Oscillation) as a way of plotting and measuring the amounts of relative global AAM (Atmospheric Angular Momentum), frictional torque and mountain torque at different phases of the cycle. They became leaders in this specialist research which has been used to assist in understanding impacts on global weather patterns and upcoming changes up to a few weeks ahead. They left NOAA several years ago and Klaus Weickmann has retired. Ed Berry continues his excellent work on the GSDM and retains his lifelong passion to develop the model and its meteorological applications further. He recently gave a brilliant presentation about the model at an AMS meeting in Chicago. This is a one hour seminar with clear charts and explanations, ending with a question and answer session. I have watched it three times already and understand a little more about the GSDM from each viewing. For anyone wishing to learn more about AAM, the torques, the GWO and how they interact with other major teleconnections like phases of the ENSO (El Nino Southern Oscillation) and the MJO (Madden Julian Oscillation) then this is absolutely essential viewing. I also strongly recommend this for more advanced viewers as well. The presentation is right up-to-date and includes the 2018 SSW (Sudden Stratospheric Warming) event and links to key issues like climate change. Much of the presentation is slanted towards the North American climate and US weather patterns but it has a global significance and includes impacts on both hemispheres. Link to full presentation (1 hour and 4 minutes): https://youtu.be/Cv5CblXbYuQ I also reviewed this presentation on the main "Telconnections: A More technical Discussion" thread. This includes some examples of the charts used in the presentation. Just click on this direct link: What is the GSDM and how does it help with subseasonal weather forecasts? - A Review of This Presentation I reviewed the whole presentation in that Teleconnections thread post, so I will not show all the slides and charts again (which you can view through that Tele thread link), accept these two: The presentation covers ENSO and the MJO - two other key components of the GSDM. Then GLAAM and the torques. There is quite a bit on the application of the GSDM to the 2017/18 winter forecasts, right up to the SSW event which had only just finished when Ed produced his presentation. There is plenty on N American climate and impacts too. It was also Klaus and Ed who devised the GWO charts which are probably better known than the GSDM itself. They went back to 1958 and produced GWO charts for all the winters (Nov to March) and some summer charts too. These are invaluable and anyone who uses analogs must refer to them as they are by far the most important guide to circulation patterns in previous winters. Zac copied all of them into the Archived Charts Library within the Research Portal - here's a direct link: Global Wind Oscillation (GWO) https://www.33andrain.com/topic/1607-archived-charts-library/?do=findComment&comment=139291 I've often posted this GWO phase space chart as have others posting on this topic: Well Ed has developed the chart a little more with this busier version in his presentation: He explains it clearly in the video. Right to finish with, just a quick look at the latest position: Just as we suggested, the GWO has been struggling to repeat its higher orbit and is tracking down now through phase 1, with slightly -ve GLAAM. it may loop back again but will look to be somewhere between neutral and the Nina attractor but probably not as -ve as in September and the first half of October. Now there is a 2 day time lag on all these charts. At first sight it looks like FT is rising and that's not what is suggested by the current position of the GWO - it could look more like phase 4 but we must examine the distribution of FT . It is strongly +ve in the mid latitudes both around 60N and 60S (the yellow, oranges and even a spot of red) but where it's important is in the tropics and it is currently -ve south of the equator and more strongly -ve (greens and blues) north of the equator. There is just a hint that it is less -ve right now - so one to monitor closely. MT is very mixed right now. Globally (GLMT - the black line) has fallen back into -ve territory and Interestingly NAMT (blue line) has just plummeted to strongly -ve in the last 2 days. EAMT (red) has managed to stay +ve but is struggling to rise much further - it may well stay slightly +ve for another day or 2. Unless FT goes more generally higher and MT assists, the GWO is not then likely to loop back to phase 4 very quickly. It's a diffficult one to call right now but at best we might manage neutral again, otherwise a longer lasting -ve phase. One last clue. This is not GLAAM itself but "global relative AAM tendency". This was strongly +ve earlier in the month, then fell back to -ve a week ago, recovered to near neutral but has fallen again this week. Now Ed's more detailed GWO chart shows us that max -ve rel tendency is in phase 8 to phase 1 where we are now. Rel tendency can move up and down very quickly. Again we need to see if the GWO goes any lower or loops back towards phase 4. Even then, only a quick climb into phase 5 would help reflecting +FT and +MT too. We may not see that until much later in December. So, please find time to watch Ed's full presentation and all this will become more meaningful. David EDIT: btw: As I expected in my last ENSO update on here a few days ago (going by the SUBs and kelvin wave no. 5), Nino 4 is falling steadily and 3.4 has dived back to 0c anomaly. Nino 3 (kw 5 is just below the surface there) has been mixed but marginally higher and Nino 1 +2 remains +ve (kw 5 has to rise there with the Ecuador coast barrier and the cold Humboldt current undercutting it) and even though it fell back it remained +ve and looks set to go higher right now. I still confidently predict that the EPAC will be the warmest region for much of the next 6 (or nearer 5 now) weeks until early January. We "might" have kw 6 developing in the far WPAC but this will take until Feb before it properly warms up the CPAC. Just a quick look down under which confirms all this. Note how the -ve anomalies behind kw5 at 150 m to 100m are continuing to expand and intensify. See my full ENSO analysis last week on here for a detailed run through of these SUBs charts. I will not look at the important atmosphere conditions right now (which are also key) but the rapidly fading MJO and declining impact of a WWB trying to form further west, do not suggest any thing to prevent the very slightly weak Nino-like conditions from weakening further to very near neutral. Link to that long ENSO post: https://www.33andrain.com/topic/1710-long-range-pattern-forecasting-thread/?do=findComment&comment=158227
  9. Welcome to the "long" post brigade! This is an outstanding post and clearly explained and well laid out. I concur with a very large part of it. Obviously we will need to closely monitor the GWO - not only the current fairly neutral orbit which some of us have been discussing in our posts on here but the orbit later in December which will be hugely important moving into mid Winter. A lot to be resolved during the next 4 weeks. David
  10. That's yet another outstanding post Tams. @sebastiaan1973 Hi Sebastiaan - good to see you being active on this forum - check out the UK and European Discussion thread which I launched about a month ago. I hope that you can make some regular contributions on there. To answer you query that you put to @Tamara - Tams never produces long range forecasts but she does provide a good indication of the likely broader patterns and changes going forward for several weeks ahead based on her excellent knowledge of the GSDM (Global Synoptic Dynamic Model), the GWO (Global Wind Oscillation), GLAAM (Global Atmospheric Angular Momentum) and the Torques. I think you asked me a similar question recently (but it may well have been another member) and I do not make LRFs either but i do produce regular posts on the background signals (teleconnections) and often focus on ENSO and the MJO. Remember it is always the teleconnections that drive the model output and not the other way around. David
  11. No time for a full update this week but the 2019 ice extent passed 10 m sq kn early yesterday. I'll show the newer improved Version 3 chart below (JAXA still use Version 2 and I'll explain the difference next time): We had been comparing 2019 to 2012 (the record low ice extent year) but 2012 continued its rapid recovery while 2019 has recently slowed from its record rate of recovery from late Oct to early Nov. 2019 has recently passed 2017, 2006 and 2010 having exceeded 2016 some time ago. So now only the 5th lowest for the date but with renewed very rapid ice growth expected during at least the next week or so, 2019 should pass another 5 or more years very quickly. This should take it to one of the best end of Nov extents of the decade - still pretty poor compared the 1980s and 1990s but excellent compared to this century's ice extent. The reason.... Some of the lowest widespread temps the Arctic region has seen for a very long time - right now and at least until month end! Others factors are important too which I'll cover in my next full report The ice distribution continues to be much stronger on the Atlantic side and the south Chukchi Sea, Bering Straits and Bering Sea are virtually ice free on the Pacific side. David
  12. I FEEL THAT THERE HAS BEEN SOME MISINTERPRETATION OF THE ENSO BASE STATE WHICH IS SKEWING SOME OF THE EARLY WINTER FORECASTS Quite a few reports on here (most often quoting tweets or other social media sources) showing medium to longer range forecasts have been assuming that the Nino or Nino-like base state will continue throughout winter. In my recent comprehensive ENSO updates on here and on the Teleconnection thread, I have been endeavouring to explain why I feel the reliance on these conditions has been somewhat misplaced. For example, El Nino type analogs have been used to show that this will be one of the key factors for a prolonged period with mostly -NAO conditions. Yes we do currently have a slightly Nino-like base state but what many seem to be ignoring is the recent trend which started about a month ago. In this post I'll have another go at demonstrating and explaining these trends. This time I'll do it in reverse and start from the bottom and work upwards. Firstly a reminder of the precise locations of the 4 Nino regions (from about 160E to 80W) as I'll be referring to these a few times below. Note that the far WPAC is not a Nino region but can still be relevant. Sub Surface Temperatures (SUBS) I used to rely far more on the NOAA output for ENSO conditions but since the Australian Bureau of Meteorology (BOM) was revamped and they upgraded their website, I've been highly impressed with their output. Here's a link to their SST and SUBs section: http://www.bom.gov.au/marine/sst.shtml Apart from the daily figures, the other charts are updated every 3 to 4 days, whereas much of the NOAA output is only done weekly and their weekly ENSO and MJO reports (each Mon/Tues) usually show data that is up to 5 to 10 days old. The BOM site also has a comprehensive archive with all the monthly SUBs charts available back to 1995 - so you can compare these for any analog matches. The excellent chart above shows us the Equatorial Pacific Ocean profile from the surface down to SUBs of 400 meters with averaged anomalies for each of the last 3 months and the current month to date (as at Nov 21st). Following the weakening El Nino (peaking around March) we have been in ENSO neutral conditions since the Spring/early Summer. In August we saw generally cooler conditions and the much more volatile EPAC was often the coldest with frequent periods with a -ve SPO (South Pacific Oscillation) helping to drive up and enhance the much cooler waters on the Humboldt/Peruvian current originating from the Southern Ocean (I did a huge post on this about a month ago on the Teleconnetion thread). At that time, the -ve SUBs at about 100 m had stretched right across the Pacific and one could be forgiven for thinking that we were heading towards La Nina conditions. That warm patch in the WPAC above 100 m up to the surface and also below 150 m down to 300 m was partly in line with Kelvin Wave number 5 (more below on that). Then during September the cool patch contracted slightly and became more confined to the CPAC and EPAC where it intensified slightly. The warm patch near the surface further west was less warm. During October we saw the more easterly warm patch expand as kelvin wave 5 pushed slowly but steadily eastwards. This raised temps across the WPAC and CPAC Nino regions leaving only the EPAC rather colder. The colder SUBs in the far west were fading. The earlier LRFs started coming out around mid-Oct and the surface did look more Nino-like at that stage except in the EPAC and that's where talk of a weak El Nino Modoki arose. However, things were already changing again and I reported on that trend nearly a month ago. That contracting colder patch in the EPAC was being steadily squeezed and lifted out just ahead of kelvin wave 5. Now things are steadily changing but we need to carefully examine the current pattern. Our kelvin wave has progressed further east through the Nino regions. The warmest spot is at around 115W but just below the surface at 75 m. It reaches the surface in the east of Nino 3.4 at 125W but more weakly further west of that (hence the rising SSTs there until the last couple of days) but is just below the surface in Nino 3 which has fallen back slightly this week (more below on the Nino regions). Note that the warmer waters have now reached Nino 1+2 and that final tiny patch of blue has all but gone. Given the pace of progression, I confidently predict that the EPAC will now stay mostly +ve for the next 4 to 6 weeks - which is one key factor in the misinterpretation by some of the forecasters and also, until a couple of days ago, some of the models and their variability wrt to NAO predictions for December. We need to consider what's happening further west to get a heads up for the next few weeks. That large patch of warmer anomalies has weakened considerably and has become much narrower - elongated from west to east. This general cooling (or less warm anomalies) is the typical pattern in the rear of this type of kelvin wave. Even Nino 4 is starting to drop back slightly from it's more strongly +ve levels. Just to the west of Nino 4 the warmest spot is "not" progressing eastwards as some were expecting. Colder SUBs are again spreading across at around 150 m and expanding and rising towards 100 m. This may not reach the surface (perhaps in the far EPAC in January but other factors need to be considered) but is helping to lower those surface anomalies. So, at this stage, we are looking at a warming trend in the EPAC but a slightly cooling trend in the CPAC/WPAC (except the far west - more on that later). I do not normally go into this micro detail but did it for two reasons in this post. One to try to show that there has been some misunderstanding of these broadly "ENSO neutral" conditions and the other to show those unfamiliar with these charts just how we can see what's going on down under and how that has an impact on SSTs. As the difference between El Nino and La Nina conditions is not much more than 1 c, these small changes are significant. With an extended period of near neutral conditions we usually see short term fluctuations between slightly more Nino-like and slightly more Nina-like conditions. These are not always picked up that well by the models and in any event, the average ENSO consensus forecasts tend to mask these small variations which can have knock on impacts on medium to longer range forecasts. I'll come on to the other factors shortly but I'll be much briefer with my comments from now on, to avoid this post from becoming too long again!. This chart covers the same period but just for the 150 m SUBs. Again we can see the trend of the lower anomalies in the EPAC steadily being squeezed/lifted out. Note how all the warmer anomalies have weakened. This is another profile of Equatorial SSTs and SUBs down to 400 m but with the current conditions (not averaged) and actual values. The top segment shows the mean temps for this date, the middle segment shows the current values and bottom segment shows the anomalies. That warmer patch at 75 m is even clearer on this chart. It is slowly drifting eastwards and rising. In fact the Ecuador coast acts as a block and the colder Humboldt/Peruvian current below the warmer waters is what will lift it to the surface and that's why Nino 1+2 should be mostly +ve until early January. Sea Surface Temperatures (SSTs) Right, now that we've seen what's going on below and how that has an impact on the surface (+ other factors from above - see later) let's move on to what many of you are much more familiar with. I said that the WPAC anomalies were just showing signs of dropping back. They are likely to drop to below +0.5 in the next 2 to 3 weeks but not in a smooth line. The main ENSO region (just for a yardstick for measuring the base state) trended upwards from mid September and as we saw that was very largely due to the kelvin wave passing through. That has just about cleared to the east now and the trend should be broadly down again for most of the next few weeks - perhaps nearer to +0.1 c to +0.2 c Further east, Nino 3 trended up to mid-Nov (just rule a line either through the lowest points or the highest points) in fits and starts. Remember, i said that the warm pool was mostly just below the surface here and only raised the surface temps slightly into +ves. The kelvin wave has not quite cleared this region yet so we may well see a continuation of the variability around the +0.2 c to + 0.4 c level (or just outside this range) through to mid-Dec before it falls to near 0.c or below. Now the big change which I've been banging on about! Nino 1+2 has been almost entirely -ve for at least the last 4 months with only brief forays into +ve territory. Repeated bouts of -ve SPO phases pushed the temps down and they struggled to recover every time the circulation pattern eased its grip. The trend was downwards until mid-Oct but the -ve SPO phases were not as strong and the waters from the Southern Ocean passed their seasonal minimums in early Oct, so the cold water upwellings were very slightly less cold. From mid-Oct the trend turned upwards but still with largely -ve anomalies until recently. Now the region is starting to see the early influence of kelvin wave 5. The upward trend will accelerate but the usual volatility in this region will continue, albeit to a lesser extent. I fully expect Nino 1+2 to have the highest +ve anomalies across all 4 Nino regions for most of the next 6 weeks or so. It's no good taking the average values of the last 3 months, 1 month or weekly periods as this masks the underlying trend (unless one compares the trend from those fixed point values). The change has been underway for nearly a month now and yet, some of the forecasts (including several from high profile commentators) have still been mentioning El Nino Modoki conditions. Please, just focus on what is actually going on. I just cannot make this point strongly enough! Now you can be forgiven for glancing at these global anomaly charts and reading them at a point in time but again the trend is so important. We still see that area of blue in the tropics/sub tropics just south of the Equator in the east and central northern SPAC (I only missed out west there!) - these have steadily weakened in the last few weeks. I've already shown that the SSTs in the WPAC and CPAC are now trending slowly downwards and you can see the +ve anomalies appearing in the EPAC. Beyond the Nino regions in the far west of the WPAC some -ve anomalies are appearing - this will need to be monitored (more below). Another highly important point that I made in several recent ENSO posts is the contrast between the temps at the Equator (from 5N to 5S) and the adjacent tropics/sub tropics from 5N to 15N and 5S to 15S When this contrast is strong with +ves in the Nino regions, this is far more conducive to tropical forcing. When it is much weaker we tend to see far less tropical forcing and below average convective activity (notwithstanding other factors - below). We not only have a steadily weakening Nino profile (even if anomalies stay marginally +ve overall) but also a much weaker contrast developing. This is yet another key reason to suggest that the broadly neutral ENSO base state will have very little impact indeed further afield. I feel that (subject to non ENSO factors) that we shall see those -ve NAO values steadily rise by the end of week 2 and through to mid to later Dec. for most of the time. The 7 day anomaly trend confirms most but not all of what I said above. The contrasts are steadily weakening. The EPAC is warming slowly while the other Nino regions are cooling, esp in the CPAC/WPAC along the Equator. Those blue -ves to the south are weak but in complete contrast to the last few months, the waters adjacent to the Chilean and Peruvian coasts are warming - so instead of feeding those cold waters into the EPAC they will be far less effective. That and the kelvin wave impact there are highly significant. The last few days has seen those far WPAC temps to recopver slightly (still -ve there). I'll comment next time on the IOD. Other Factors: In my previous ENSO updates, I focused just as much on what is going on above the surface, which has a significant impact on ENSO conditions, sometimes even more so. To avoid prolonging this post even further, I'll merely skip through these this time and then focus much more on them in my next ENSO update (in a week or two). For a start, those kelvin waves beneath the surface are generated from above the surface. This chart is from NOAA's most recent weekly ENSO report. KW 5 is near the bottom of the chart represented by the thick black broken line. When these are generated in the far WPAC they are like a weight in the atmosphere and they compress the surface layers of the ocean (I'll do a post on them on the Tele thread at some time quite soon and there's a great YouTube video somewhere). The higher SSTs at the top are pushed down to lower levels, increasing the SUBs but as we saw, as the wave passes, colder waters return. In fact the narrow spaced more dotted lines on the charts are the areas where those colder patches are located. So we can see KW 5 moving steadily eastwards and intensifying (until recently - as we now know that it has weakened somewhat in the last couple of weeks) as it approached the CPAC and now the EPAC. Then we have the colder waters following on behind, currently centred at 160W (hence Nino 4 just starting to see lower +ve anomalies). Now to read this chart properly and to get a heads up on what to expect going forward we need to look at the progression through the dates - so we really take a route from west-northwest to east-southeast. Right now there is no immediate sign of another significant KW passing through the Pacific - there may be minor ones just as you can see in the middle of the chart with two kws struggling to strengthen in June and July, which was the period where the El Nino phase had passed and ENSO neutral conditions became established. Further up the chart we see the last proper KW which passed through during the peak of the weak El Nino from Jan to Apr. Other key factors are the MJO but the current moderate amplitude episode has continued to weaken as it steadily fades and passes out of the Pacific. Given the lag time we may still see modest impacts for another few days but most MJO forecasts are now showing very weak conditions. Another key point that some commentators have seemed to miss is the stubbornly stationary standing wave in the Indian Ocean. This is effectively the colder, dry, HP phase of the MJO and seems to have suppressed the warmer, moister, LP phases as they reach the Pacific. It looks like this "suppression" of tropical Pacific activity will continue for some time and even if we see a promising phase in the next cycle it too may quickly fade (not certain at this stage - due around the turn of the year). This suppressed activity is very likely connected to the ocean-atmosphere disconnect that we've seen for many months with a lack of the normally anticipated responses. Something I've been studying and I'll be placing several more recent papers into the Research Portal followed by a review of them and other existing studies in a Tele thread post on this topic early in the New Year - some fascinating causes and new theories! We have also seen a slight move towards what would normally be favouring westerly wind bursts (often related to MJO and kelvin wave activity) but, probably for the same reasons, these too, seems to be suppressed and promising signs quickly fade again. So what controls or influences these patterns. A number of us have done posts on the GWO, GLAAM and the torques - yet another area that some seem to have misinterpreted recently. Yes, the GWO has risen into a more neutral orbit but to say it's moving towards the "Nino attractor" phases, that's phases 5 to 8, looks wide of the mark to me and several others of us on this thread like Tams @Tamara and Tom @Isotherm both of whom I have the highest respect for. Yes, the current orbit looks like we may see a brief repeat in the next few days, possibly even marginally higher than the last one but nothing currently suggests a real break out into a meaningful higher orbit. Mountain Torque has briefly gone +ve but Gravity Wave Drag is falling now and that's almost always a strong sign that EAMT will follow a day or two later (I've studied this very strong correlation for over 15 months now and will post on it in due course). More significantly, Frictional Torque has struggled up to neutral overall but looks set to fall back in the next few days. In fact FT is at it's lowest in the key area of the northern tropics/sub tropics which is another drag on any sustained +ve GLAAM. To me, almost all the indicators point towards a really subdued neutral ENSO base state and we are likely to see brief periods of marginally Nina-like conditions alternating with brief periods of slightly more Nino-like conditions but nothing to suggest that any significant wider impacts can be expected. Of course things can change - but not overnight. We need GLAAM and the GWO to see a much more +ve burst with rising FT and MT for a more sustained period. That I/O standing wave needs to wake up and the suppression in the Pacific and the ocean-atmosphere disconnect need to change. That's why, although I never produce LRFs, that I favour the second half of winter for any more significant colder spells in neCONUS and W.Eur/UK. David
  13. @Tamara @Isotherm Tams and Tom, I fully concur with your posts above. I'm suffering a bit from over posting exhaustion, so I'll be particularly brief. In essence, the thrust of all our recent posts on here or the Teleconnections thread relating to the GWO, GLAAM, the torques, the ENSO state, the MJO, other oscillations, the Stratosphere and on the discussion wrt a minor warming event or the highly unlikely early SSW (+ my additional comments wrt to Arctic sea ice extent and N hem snow cover) have been looking at the current patterns and developments and at the broader scale patterns and general expectations through December and not on the micro scale running through the next 2 weeks. This seems to have produced some misunderstanding wrt to timing issues although I feel that we all made this clear during our respective posts. @OHweather an excellent post by you too earlier today. I agree that we are having a very temporary rise in MT - particularly EAMT but, like you, I do not believe that this is sustainable beyond 2 to 3 days or so. I haven't got time now but will probably produce a longer response later this weekend. David
  14. One last quick post before I take a break for a day or so (try and keep me away!). Following my long post last night on assessing analog years (which you pinned to the top of the page - for now!), I provided a large number of links to examine the teleconnections to make more accurate and realistic comparisons. I'll just show 2 charts for 1995/96 with brief comments but I would like to see others use these assessment tools too - its both fun and very informative - indeed once you have done it once it gets pretty infectious and it may well catch on! GLAAM rose from neutral into a higher orbit - about 1.5 octants above where it is now and rose into a higher orbit during December before falling back sharply towards the end of December and into a low (-ve) orbit for the remainder of that winter. 1995/96 was entirely in a La Nina from Fall to Spring but it was mostly a weak one but that explains why there was only a 3 week period in the Nino attractor - GLAAM overall was conducive to maintain the La Nina conditions. Early ice growth in 1995 was well ahead of 2019 at this stage and near average for that stage in the 1990s with about 1 m sq km more ice than today. So whilst a marginally better analog than 2002/3, based on just these 3 important indicators, 1995/6 is not looking like a good one. I'll leave it up to others to dig out some of the other teleconnection comparisons. Sorry to knock it down but as I said, it can be fun and rewarding just to do these comparisons. David
  15. Just a quick one on the latest ENSO model consensus. The latest IRI/CPC monthly update came out on Tuesday/Wednesday. I show this with the October chart below for a quick comparison. My comments are in between and below. Link to their site: https://iri.columbia.edu/our-expertise/climate/forecasts/enso/current/ We need to remember that the 3 month rolling periods have advanced by one when aligning the two charts. These only relate to the Nino 3.4 region. Following the slight rise from Sept to Oct (the current observation point) we can compare the two OND to NDJ forecast trends. At first sight they look very similar but note that the spread is slightly tighter now. The outliers have gone with just one model being slightly -ve and none above +0.75c. The statistical average (which should only be taken to see an overall trend) - the thick pale green line drifts slowly but steadily down right through to the end of summer 2020 but still maintains more or less ENSO neutral conditions. Only 2 outliers go for a break out to over +1c and one of these quickly drops back. Just one goes for nearer to -1c by next Spring but 6 or 7 more go for more Nina-like conditions as we more toward next summer. Overall, the medium to longer term outlook is drifting more towards Nina conditions rather than Nino conditions. While the consensus is that we remain largely, if not entirely in ENSO neutral conditions throughout the winter and into Spring, this masks shorter periods of very slightly more Nino-like conditions (as we have been seeing recently) and more Nina-like conditions as we may see in December (perhaps only very briefly) should GLAAM fall into the GWO Nina attractor for more than just a few days. This was excellently illustrated by Tams @Tamara in her post earlier today and several others of us in previous recent posts. ENSO conditions are weak and these small variations between Nino-like and Nina-like are typical during an extended period of near neutral conditions. Most of the ENSO models do not factor in changes in GLAAM and the torques particularly well and are often slow to respond. This is another teleconnection area where we can usually get a heads up on upcoming changes. We need to take account of other factors too, like the MJO but with that dying now as it moves out of its Pacific phase, it looks like we shall remain in a pretty benign tropical pattern for several weeks (at least). David
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